Common variants in immune and DNA repair genes and risk for human papillomavirus persistence and progression to cervical cancer

A Comprehensive Integration of Data Regarding the Correlation of TNF-α rs1800629 Polymorphism with Susceptibility to Cervical Cancer

BACKGROUND

Cervical cancer, globally, ranks as the runner-up among the most prevalent forms of cancer affecting women. The role of the tumor necrosis factor alpha (TNF-α) polymorphism in the susceptibility to cervical cancer has been a subject of interest. However, the current evidence regarding this association remains inconclusive.

METHODS

To address this uncertainty, eligible studies were systematically searched and retrieved from various databases including Cochrane Library, EMBASE, PubMed, Web of Science, CNKI, and Wanfang database. The search was conducted until September 01, 2023. The collected literature was then subjected to independent analysis by two authors. The pooled odds ratio along with the corresponding 95% confidence interval was calculated using different genetic models. Additionally, sensitivity and cumulative analyses were performed to assess the stability of the obtained results.

RESULTS

A total of 29 case-control studies involving 8850 cases and 9286 controls were included in the present analysis. The findings revealed that the TNF-α rs1800629 polymorphism increased the risk of cervical cancer under the allele genetic model (A vs. G: OR = 1.277, 95% CI = 1.104-1.477, P = 0.001) in the general population. Subgroup analysis based on ethnicity demonstrated that this polymorphism was associated with an increased risk of cervical cancer in Caucasian and African women, but not in Asians. Furthermore, subgroup analysis based on country of origin indicated a significant correlation between the TNF-α rs1800629 polymorphism and an increased risk of cervical cancer in American and Chinese women, but not in Iranian women.

CONCLUSIONS

The findings from this meta-analysis suggest that the TNF-α rs1800629 polymorphism is a risk factor for cervical cancer in the general population, particularly in Caucasian and African women. However, further well-designed studies are warranted to validate these findings.

Variations in Genes Encoding Human Papillomavirus Binding Receptors and Susceptibility to Cervical Precancer

BACKGROUND

Cervical cancer oncogenesis starts with human papillomavirus (HPV) cell entry after binding to host cell surface receptors; however, the mechanism is not fully known. We examined polymorphisms in receptor genes hypothesized to be necessary for HPV cell entry and assessed their associations with clinical progression to precancer.

METHODS

African American women (N = 1,728) from the MACS/WIHS Combined Cohort Study were included. Two case-control study designs were used-cases with histology-based precancer (CIN3+) and controls without; and cases with cytology-based precancer [high-grade squamous intraepithelial lesions (HSIL)] and controls without. SNPs in candidate genes (SDC1, SDC2, SDC3, SDC4, GPC1, GPC2, GPC3, GPC4, GPC5, GPC6, and ITGA6) were genotyped using an Illumina Omni2.5-quad beadchip. Logistic regression was used to assess the associations in all participants and by HPV genotypes, after adjusting for age, human immunodeficiency virus serostatus, CD4 T cells, and three principal components for ancestry.

RESULTS

Minor alleles in SNPs rs77122854 (SDC3), rs73971695, rs79336862 (ITGA6), rs57528020, rs201337456, rs11987725 (SDC2), rs115880588, rs115738853, and rs9301825 (GPC5) were associated with increased odds of both CIN3+ and HSIL, whereas, rs35927186 (GPC5) was found to decrease the odds for both outcomes (P value ≤ 0.01). Among those infected with Alpha-9 HPV types, rs722377 (SDC3), rs16860468, rs2356798 (ITGA6), rs11987725 (SDC2), and rs3848051 (GPC5) were associated with increased odds of both precancer outcomes.

CONCLUSIONS

Polymorphisms in genes that encode binding receptors for HPV cell entry may play a role in cervical precancer progression.

IMPACT

Our findings are hypothesis generating and support further exploration of mechanisms of HPV entry genes that may help prevent progression to cervical precancer.

Polymorphisms in the Nonhomologous End-joining DNA Repair Pathway are Associated with HPV Integration in Cervical Dysplasia

Previous evidence indicates that human papillomavirus (HPV) integration status may be associated with cervical cancer development and progression. However, host genetic variation within genes that may play important roles in the viral integration process is understudied. The aim of this study was to examine the association between HPV16 and HPV18 viral integration status and SNPs in nonhomologous-end-joining (NHEJ) DNA repair pathway genes on cervical dysplasia. Women enrolled in two large trials of optical technologies for cervical cancer detection and positive for HPV16 or HPV18 were selected for HPV integration analysis and genotyping. Associations between SNPs and cytology (normal, low-grade, or high-grade lesions) were evaluated. Among women with cervical dysplasia, polytomous logistic regression models were used to evaluate the effect of each SNP on viral integration status. Of the 710 women evaluated [149 high-grade squamous intraepithelial lesion (HSIL), 251; low-grade squamous intraepithelial lesion (LSIL, 310 normal)], 395 (55.6%) were positive for HPV16 and 192 (27%) were positive for HPV18. Tag-SNPs in 13 DNA repair genes, including RAD50, WRN, and XRCC4, were significantly associated with cervical dysplasia. HPV16 integration status was differential across cervical cytology, but overall, most participants had a mix of both episomal and integrated HPV16. Four tag-SNPs in the XRCC4 gene were found to be significantly associated with HPV16 integration status. Our findings indicate that host genetic variation in NHEJ DNA repair pathway genes, specifically XRCC4, are significantly associated with HPV integration, and that these genes may play an important role in determining cervical cancer development and progression.

PREVENTION RELEVANCE

HPV integration in premalignant lesions and is thought to be an important driver of carcinogenesis. However, it is unclear what factors promote integration. The use of targeted genotyping among women presenting with cervical dysplasia has the potential to be an effective tool in assessing the likelihood of progression to cancer.

Interleukin 10 rs1800896 and interleukin 1B rs16944 polymorphisms and the risk of cervical cancer

BACKGROUND

The purpose of this study was to evaluate the relationships between interleukin 10 (IL10) (rs1800896) and interleukin 1B (IL1B) (rs16944) genetic polymorphisms and the risk for cervical cancer in a cohort of women from Croatia.

METHODS

A case-control study of 81 patients with cervical cancer and 80 age-matched healthy controls was performed. We collected peripheral blood samples, extracted deoxiribonucleic acid (DNA), and analyzed two single-nucleotide polymorphisms (SNPs) rs1800896 and rs16944 using TaqMan assays (Fa. Thermo Fisher Scientific, Waltham, MA, USA) and real-time polymerase chain reaction (PCR). We investigated a possible association between two cytokine genetic polymorphisms and the occurrence of cervical cancer.

RESULTS

Our results showed no significant difference in the frequency of IL10 (rs1800896) and IL1B (rs16944) genotypes between the patients and the controls (χ2 test, P < 0.05).

CONCLUSION

In this study, no association was found between IL10 rs1800896 and IL1B rs16944 polymorphisms and cervical cancer development.

The Drivers, Mechanisms, and Consequences of Genome Instability in HPV-Driven Cancers

Simple Summary

Cells infected with high-risk human papillomaviruses (HPV) can accumulate DNA damage and eventually transform into HPV-driven cancers. Genome instability, or the progressive accumulation of DNA alterations (e.g., mutations), in HPV-infected cells is directly induced by the HPV genes and indirectly promoted by HPV infection through the consequences of chronic infection maintenance, increased cell growth, and accumulation of damaging mutations in genes that themselves affect genome instability. While the HPV genome typically exists as a separate entity within cells, genome instability increases the chances of HPV integrating within the host (human) genome, which is common in HPV-induced cancers. The DNA regions surrounding HPV integrations are unstable and can undergo complex alterations that affect both human and HPV genes. This review discusses HPV-dependent and -independent drivers and mechanisms of genome instability in HPV-driven cancers, both globally and around sites of HPV integration, and describes the changes induced in the tumour genome.

Abstract

Human papillomavirus (HPV) is the causative driver of cervical cancer and a contributing risk factor of head and neck cancer and several anogenital cancers. HPV’s ability to induce genome instability contributes to its oncogenicity. HPV genes can induce genome instability in several ways, including modulating the cell cycle to favour proliferation, interacting with DNA damage repair pathways to bring high-fidelity repair pathways to viral episomes and away from the host genome, inducing DNA-damaging oxidative stress, and altering the length of telomeres. In addition, the presence of a chronic viral infection can lead to immune responses that also cause genome instability of the infected tissue. The HPV genome can become integrated into the host genome during HPV-induced tumorigenesis. Viral integration requires double-stranded breaks on the DNA; therefore, regions around the integration event are prone to structural alterations and themselves are targets of genome instability. In this review, we present the mechanisms by which HPV-dependent and -independent genome instability is initiated and maintained in HPV-driven cancers, both across the genome and at regions of HPV integration.

Prioritization and Meta-analysis of regulatory SNPs identified IL6, TGFB1, TLR9 and MMP7 as significantly associated with cervical cancer

Cervical cancer is a leading women cancer globally with respect to both incidence and mortality. Its increased risk has been linked with HPV infection and genetic variations like single nucleotide polymorphisms (SNPs). Although, studies have been published which evaluates the effect of SNPs in a few candidate genes, however the role of number of regulatory SNPs (rSNPs) in cervical cancer is not available. As literature evidence has shown that non-coding rSNPs are related with increasing cervical cancer risk, we undertook this study to prioritize the important rSNPs and elucidate their role. A search was conducted in PubMed up to December 2020, which led to the identification of 263 articles and 969 SNPs in the non-coding region. These 969 SNPs were analysed through rSNPBase and RegulomeDB, leading to identification of 105 rSNPs. Afterwards, a regulatory module was constructed using protein-protein interaction data and a hub of highly interacting 23 target genes (corresponding to 34 rSNPs) was identified using MCODE. To further understand the mechanism of action of the 34 rSNPs, their transcription factor information with respect to cervical cancer was retrieved. To evaluate the pooled effect of these prioritized polymorphisms in cervical cancer patients, a meta-analysis was performed on 10,537 cases and 11,252 controls from 30 studies corresponding to 8 rSNPs. It led to identification of polymorphisms in IL6 (rs2069837), TGFB1 (rs1800469), TLR9 (rs187084) and MMP7 (rs11568818) which are significantly (p < 0.05) associated with increased cervical cancer risk at the population level. Overall, the study demonstrates that rSNPs targeting immune and inflammatory genes (IL1B, IL6, IL10, IL18, TGFB1, CCR5, CD40, TLR9, and MMP7) are associated with cervical cancer.

Genetic polymorphisms in DNA repair genes and their association with risk of cervical cancer: A systematic review and meta-analysis

BACKGROUND

There have been a large number of epidemiologic studies regarding the association between genetic polymorphisms in DNA repair genes and onset of cervical cancer. However, results are inconsistent.

METHODS

Articles published before June 2021 and regarding genetic polymorphisms in DNA repair genes and cervical cancer were searched in following databases: PubMed, Web of Science, Google Scholar, and CNKI. With at least three articles for each polymorphism, we made meta-analysis to compute multivariate odds ratios (ORs) and their 95% confidence intervals (CIs).

RESULTS

The present study showed significant associations between XRCC1 Arg399Gln polymorphisms and risk of cervical cancer in Asian, whereas no significant association between them were showed in Caucasian (Asian: GA vs. GG: OR = 1.27, 95%CI 1.06-1.52; AA vs. GG: OR = 1.91, 95%CI 1.29-2.83; GA + AA vs. GG: OR = 1.36, 95%CI 1.12-1.65; AA vs. GG + GA: OR = 1.66, 95%CI 1.17-2.37; Caucasian: GA vs. GG: OR = 1.08, 95%CI 0.83-1.41; AA vs. GG: OR = 2.18, 95%CI 0.75-6.31; GA + AA vs. GG: OR = 1.23, 95%CI 0.85-1.78; AA vs. GG + GA: OR = 1.70, 95%CI 0.69-4.18). In addition, there were significant associations between ERCC2 rs13181 polymorphisms and risk of cervical cancer in Asian (AC vs AA: OR = 0.53, 95%CI 0.37-0.75, I²  = 0.0%, p value of Q test = 0.847; AC + CC vs AA: OR = 0.50, 95%CI 0.36-0.70, I²  = 0.0%, p value of Q test = 0.856).

CONCLUSIONS

The meta-analysis showed that there were significant associations between XRCC1 Arg399Gln and ERCC2 rs13181 polymorphisms and risk of cervical cancer.

Gene expression profiling of HPV-associated cervical carcinogenesis in formalin-fixed paraffin-embedded (FFPE) tissues using the NanoString nCounterTM platform

Infection by high-risk human papillomavirus (HPV) causes genetic alterations in host cervical cells with consequent changes in gene expression affecting downstream molecular pathways, leading to the development of cervical cancer. In this exploratory study, we aimed to identify the perturbed cellular pathways during the various stages of cervical carcinogenesis. Total RNA was extracted from three formalin-fixed paraffin-embedded (FFPE) samples each of normal cervix, HPV-infected low-grade squamous intraepithelial lesion (LSIL), high-grade SIL (HSIL) and squamous cell carcinoma (SCC). Gene expression profiling was performed using the 770-gene panel from NanoString nCounter® PanCancer Pathways Panel to identify differentially expressed genes (DEGs) and significantly associated pathways in each stage of cervical cancer development. We identified 121 DEGs involved in cervical carcinogenesis. In the transformation from normal cells to LSIL, the MAPK, transcriptional misregulation and JAK-STAT pathways are implicated, while IL1B may promote inflammation and indirectly activates MMP9, resulting in collagen breakdown and cell migration. The cell cycle - apoptosis pathway with upregulation of E2F1 and MCM2, and DNA repair genes BRCA2-BRIP1 and FANCA are crucial during the progression from LSIL to HSIL. In the final stage of progression to SCC, the cell cycle and signaling pathways, as well as upregulation of c-MYC appear essential. In conclusion, archived FFPE-derived tissue samples are a valuable resource for gene expression profiling. The postulated dysregulated pathways and genes provide a guide of the molecular mechanisms that may be involved in the development of HPV-associated cervical cancer, for further investigation and validation studies.

Type I Interferon and the Spectrum of Susceptibility to Viral Infection and Autoimmune Disease: A Shared Genomic Signature

Type I interferons (IFN-I) and their cognate receptor, the IFNAR1/2 heterodimer, are critical components of the innate immune system in humans. They have been widely explored in the context of viral infection and autoimmune disease where they play key roles in protection against infection or shaping disease pathogenesis. A false dichotomy has emerged in the study of IFN-I where interferons are thought of as either beneficial or pathogenic. This 'good or bad' viewpoint excludes more nuanced interpretations of IFN-I biology - for example, it is known that IFN-I is associated with the development of systemic lupus erythematosus, yet is also protective in the context of infectious diseases and contributes to resistance to viral infection. Studies have suggested that a shared transcriptomic signature underpins both potential resistance to viral infection and susceptibility to autoimmune disease. This seems to be particularly evident in females, who exhibit increased viral resistance and increased susceptibility to autoimmune disease. The molecular mechanisms behind such a signature and the role of sex in its determination have yet to be precisely defined. From a genomic perspective, several single nucleotide polymorphisms (SNPs) in the IFN-I pathway have been associated with both infectious and autoimmune disease. While overlap between infection and autoimmunity has been described in the incidence of these SNPs, it has been overlooked in work and discussion to date. Here, we discuss the possible contributions of IFN-Is to the pathogenesis of infectious and autoimmune diseases. We comment on genetic associations between common SNPs in IFN-I or their signalling molecules that point towards roles in protection against viral infection and susceptibility to autoimmunity and propose that a shared transcriptomic and genomic immunological signature may underlie resistance to viral infection and susceptibility to autoimmunity in humans. We believe that defining shared transcriptomic and genomic immunological signatures underlying resistance to viral infection and autoimmunity in humans will reveal new therapeutic targets and improved vaccine strategies, particularly in females.

A meta-analysis of XRCC1 single nucleotide polymorphism and susceptibility to gynecological malignancies

BACKGROUND

Gynecological malignant tumor is a serious threat to women's health, cervical cancer, endometrial cancer and ovarian cancer are the most common. The eponymous protein encoded by the XRCC1 (X-ray repair cross complementation 1) gene is an important functional protein in the process of single-stranded DNA damage. Non-synonymous mutations of XRCC1 gene cause amino acid sequence changes that affect protein function and DNA repair ability, and may affect the interaction with other DNA repair proteins, leading to increased risk of tumor development. Many studies have assessed the association between XRCC1 gene polymorphism and the risk of cancer in the female reproductive system, but the results have been inconclusive. In this study, the relationship between XRCC1 Arg399Gln, Arg194Trp, Arg280His single nucleotide polymorphisms and susceptibility to gynecological malignancies was further explored by meta-analysis.

METHODS

English database: Pubmed, Medline, Excerpta Medica Database, Cochrance, etc; Chinese database: China national knowledge infrastructure, Wanfang Database, etc. STATA14 was used for statistical analysis, such as odd ratio (OR) value, subgroup analysis, heterogeneity test, sensitivity analysis, and publication bias.

RESULTS

In gynecologic cancers, the allele frequency difference of Arg399Gln case control group was statistically significant (GvsA: P = .007). There was no significant difference in allele frequency in the Arg194Trp and Arg280His case control groups (P = .065, 0.198). In different gene models, Arg399Gln was significantly correlated with gynecologic cancers susceptibility (GGvs AA: OR 0.91; 95% confidence interval [CI], 0.85 0.98); Arg194Trp was significantly correlated with gynecologic cancers susceptibility (CCvs TT: OR 0.94; 95% CI 0.88,1.00; CCvs CT: OR 0.97; 95% CI 0.90, 1.05); Arg280His was significantly correlated with gynecologic cancers susceptibility (GGvs AA: OR 0.98; 95% CI 0.94, 1.02; GGvs GA: OR 1.00;95% CI 0.97, 1.04). In the subgroup analysis, Arg399Gln and Arg194Trp were significantly correlated with gynecologic cancers susceptibility in the Asian race (P = .000, 0.049). In the analysis of different cancer subgroups, Arg399Gln and cervical cancer susceptibility were statistically significant (P = .039). Arg194Trp and endometrial cancer susceptibility were statistically significant (P = .033, 0.001).

CONCLUSIONS

XRCC1 Arg399Gln, Arg194Trp, Arg280His single nucleotide polymorphisms were associated with gynecologic cancer susceptibility. Arg399Gln genotype was statistically significant in relation to cervical cancer susceptibility. Arg194Trp genotype was statistically significant in relation to endometrial cancer susceptibility.

Genetic Predisposition to Persistent Human Papillomavirus-Infection and Virus-Induced Cancers

Human papillomaviruses (HPVs) are the most common sexually transmitted pathogens worldwide and among the more than 200 identified HPV types, approximately 15 high risk (HR-HPV) types are oncogenic, being strongly associated with the development of cervical cancer, anogenital cancers and an increasing fraction of head and neck squamous cell carcinomas (HNSCC). HPV-associated cervix cancer accounts for 83% of HPV-attributable cancers, and more than two-thirds of those cases occur in developing countries. Despite the high frequency of HPV infections, in most cases, the virus is cleared by the host immune response and only a small proportion of infected individuals develop persistent infections that can result in malignant transformation, indicating that other elements, including biological, genetic and environmental factors may influence the individual susceptibility to HPV-associated cancers. Previous studies have quantified that heritability, in the form of genetic variants, common in the general population, is implicated in nearly 30% of cervical cancers and a large number of studies conducted across various populations have identified genetic variants that appear to be associated with genes that predispose or protect the host to HPV infections thereby affecting individual susceptibility to HPV-associated cancers. In this article, we provide an overview of gene association studies on HPV-associated cancers with emphasis on genome-wide association study (GWAS) that have identified novel genetic factors linked to HPV infection or HPV-associated cancers.

Genetic association studies of alterations in protein function expose recessive effects on cancer predisposition

The characterization of germline genetic variation affecting cancer risk, known as cancer predisposition, is fundamental to preventive and personalized medicine. Studies of genetic cancer predisposition typically identify significant genomic regions based on family-based cohorts or genome-wide association studies (GWAS). However, the results of such studies rarely provide biological insight or functional interpretation. In this study, we conducted a comprehensive analysis of cancer predisposition in the UK Biobank cohort using a new gene-based method for detecting protein-coding genes that are functionally interpretable. Specifically, we conducted proteome-wide association studies (PWAS) to identify genetic associations mediated by alterations to protein function. With PWAS, we identified 110 significant gene-cancer associations in 70 unique genomic regions across nine cancer types and pan-cancer. In 48 of the 110 PWAS associations (44%), estimated gene damage is associated with reduced rather than elevated cancer risk, suggesting a protective effect. Together with standard GWAS, we implicated 145 unique genomic loci with cancer risk. While most of these genomic regions are supported by external evidence, our results also highlight many novel loci. Based on the capacity of PWAS to detect non-additive genetic effects, we found that 46% of the PWAS-significant cancer regions exhibited exclusive recessive inheritance. These results highlight the importance of recessive genetic effects, without relying on familial studies. Finally, we show that many of the detected genes exert substantial cancer risk in the studied cohort determined by a quantitative functional description, suggesting their relevance for diagnosis and genetic consulting.

An Immune-Gene-Based Classifier Predicts Prognosis in Patients With Cervical Squamous Cell Carcinoma

Objective: Immunity plays a vital role in the human papilloma virus (HPV) persistent infection, and closely associates with occurrence and development of cervical squamous cell carcinoma (CSCC). Herein, we performed an integrated bioinformatics analysis to establish an immune-gene signature and immune-associated nomogram for predicting prognosis of CSCC patients. Methods: The list of immunity-associated genes was retrieved from ImmPort database. The gene and clinical information of CSCC patients were obtained from The Cancer Genome Atlas (TCGA) website. The immune gene signature for predicting overall survival (OS) of CSCC patients was constructed using the univariate Cox-regression analysis, random survival forests, and multivariate Cox-regression analysis. This signature was externally validated in GSE44001 cohort from Gene Expression Omnibus (GEO). Then, based on the established signature and the TCGA cohort with the corresponding clinical information, a nomogram was constructed and evaluated via Cox regression analysis, concordance index (C-index), receiver operating characteristic (ROC) curves, calibration plots and decision curve analyses (DCAs). Results: A 5-immune-gene prognostic signature for CSCC was established. Low expression of ICOS, ISG20 and high expression of ANGPTL4, SBDS, LTBR were risk factors for CSCC prognosis indicating poor OS. Based on this signature, the OS was significantly worse in high-risk group than in low-risk group (p-value < 0.001), the area under curves (AUCs) for 1-, 3-, 5-years OS were, respectively, 0.784, 0.727, and 0.715. A nomogram incorporating the risk score of signature and the clinical stage was constructed. The C-index of this nomogram was 0.76. AUC values were 0.811, 0.717, and 0.712 for 1-, 3-, 5-years OS. The nomogram showed good calibration and gained more net benefits than the 5-immune-gene signature and the clinical stage. Conclusion: The 5-immune-gene signature may serve as a novel, independent predictor for prognosis in patients with CSCC. The nomogram incorporating the signature risk score and clinical stage improved the predictive performance than the signature and clinical stage alone for predicting 1-year OS.

Whole-exome sequencing reveals the etiology of the rare primary hepatic mucoepidermoid carcinoma

Background

Primary hepatic mucoepidermoid carcinoma (HMEC) is extremely rare and the molecular etiology is still unknown. The CRTC1-MAML2 fusion gene was previously detected in a primary HMEC, which is often associated with MEC of salivary gland in the literature.

Methods

A 64-year-old male was diagnosed with HMEC based on malignant squamous cells and mucus-secreting cells in immunohistochemical examination. Fluorescence in situ hybridization (FISH) was used to detect the CRTC1-MAML2 fusion gene in HMEC. Whole-exome sequencing and Sanger sequencing were used to reveal the molecular characteristics of HMEC and analysis was performed with public data. Pedigree investigation was performed to identify susceptibility genes.

Results

Hematoxylin–eosin staining and immunohistochemistry revealed that the tumor cells were composed of malignant epidermoid malignant cells and mucous cells, indicating a diagnosis of HMEC. The CRTC1-MAML2 fusion gene was not detected in the primary HMEC, and somatic mutations in GNAS, KMT2C and ELF3 genes were identified by sequencing. Analyses of public data revealed somatic GNAS alterations in 2.1% hepatobiliary tumors and relation with parasite infection. Heterozygous germline mutations of FANCA, FANCI, FANCJ/BRIP1 and FAN1 genes were also identified. Pedigree investigation verified that mutation of Fanconi’s anemia susceptibility genes were present in the pedigree.

Conclusions

Here we provide the first evidence of the molecular etiology of a rare HMEC associated with germline Fanconi’s anemia gene mutations and somatic GNAS R201H mutation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-021-01086-3.

TCF7L1 Genetic Variants Are Associated with the Susceptibility to Cervical Cancer in a Chinese Population

Background

Cervical cancer (CC) is the second most common tumor in women worldwide. Studies have been accepted that genetic variations play an important role in the development of CC. The aim of this study was to evaluate the impact of TCF7L1 variants on CC risk.

Methods

508 patients of cervical cancer and 497 healthy subjects were recruited to determine the impact of TCF7L1 polymorphisms on CC susceptibility. The associations were investigated by computing odds ratios (ORs) and 95% confidence intervals. The effect of SNP-SNP interactions on CC risk was explored by multifactor dimensionality reduction analysis.

Results

Our study showed that rs11904127 (OR 0.79, p = 0.010) and rs62162674 (OR 0.82, p = 0.044) of TCF7L1 significantly decreased cervical cancer risk. Stratified analysis indicated that rs11904127 and rs62162674 present decreased susceptibility to CC in age > 51 years (OR 0.74, p = 0.019; OR 0.72, p = 0.014, respectively). Haplotype analyses revealed that G_rs2366264T_rs11689667C_rs62162674 has a lower risk to cervical cancer (OR = 0.43, p = 0.018). Besides, there is strong interaction of rs11904127 and rs2366264.

Conclusion

Rs11904127 and rs62162674 in TCF7L1 are related to cervical cancer. We suggest that these variants can be used as prognostic markers for judging the susceptibility to cervical cancer.

APOBEC: A molecular driver in cervical cancer pathogenesis

Cervical cancer is one of the foremost common cancers in women. Human papillomavirus (HPV) infection remains a major risk factor of cervical cancer. In addition, numerous other genetic and epigenetic factors also are involved in the underlying pathogenesis of cervical cancer. Recently, it has been reported that apolipoprotein B mRNA editing enzyme catalytic polypeptide like (APOBEC), DNA-editing protein plays an important role in the molecular pathogenesis of cancer. Particularly, the APOBEC3 family was shown to induce tumor mutations by aberrant DNA editing mechanism. In general, APOBEC3 enzymes play a pivotal role in the deamination of cytidine to uridine in DNA and RNA to control diverse biological processes such as regulation of protein expression, innate immunity, and embryonic development. Innate antiviral activity of the APOBEC3 family members restrict retroviruses, endogenous retro-element, and DNA viruses including the HPV that is the leading risk factor for cervical cancer. This review briefly describes the pathogenesis of cervical cancer and discusses in detail the recent findings on the role of APOBEC in the molecular pathogenesis of cervical cancer.

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APOBEC enzymes deaminate cytidine to uridine and control diverse biological processes including viral restriction.

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APOBEC3, DNA/RNA-editing enzyme plays an important role in the molecular pathogenesis of cervical cancer.

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APOBEC3-mediated DNA editing leads to the accumulation of somatic mutations in tumors and HPV genome.

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Deregulation of APOBEC3 family genes cause genomic instability and result in drug resistance, and immune-evasion in tumors.

Human Leukocyte Antigen (HLA) Class II -DRB1 and -DQB1 Alleles and the Association with Cervical Cancer in HIV/HPV Co-Infected Women in South Africa

Background: A subset of women who are co-infected with Human Immunodeficiency Virus type 1 (HIV) and Human papillomavirus (HPV), progress rapidly to invasive cervical cancer regardless of antiretroviral therapy (ART) or immune status. We posit that HIV/HPV co-infection along with specific host HLA II -DRB1 and -DQB1 alleles play a major role in cervical cancer development.

Methodology: We conducted a hospital-based genetic susceptibility case-control study in Cape Town, South Africa. We recruited 256 women of the same race, from which a total of 624 HLA-DRB1 and -DQB1 class II genotypes were studied. We characterized HLA II candidate genes using PCR based, Luminex intermediate resolution genotyping and confirmed significant associated genotypes at four-digit resolution by high resolution gel typing. We analyzed 160 alleles from cancer, 64 alleles from pre-cancer and 400 alleles from healthy control women. Whole blood was used for HIV antibody test and HLA II typing. Cervical tumor tissue biopsies were used for HPV genotyping. Tests were statistically significant if p<0.05.

Results: Women who were co-infected with HIV/HPV had advanced cervical disease compared to women who were HIV negative. HLA class II -DQB1*03:01 and -DQB1*06:02 alleles were associated with cervical cancer in HIV/HPV co-infected women (p=0.001 and p<0.0001, respectively) while HLA class II -DRB1*13:01 and -DQB1*03:19 were rare or absent in women with cervical disease when compared to the control population (p=0.012 and 0.011, respectively).

Conclusion: We describe associations between HLA class II genotypes with cervical cancer, or likely protection from cervical cancer disease in HIV/HPV co-infected South African women. Identifying mechanisms that give rise to this likely protective HLA association will provide insight into development of immune-based prevention measures.

Novel Genomic Biomarker Candidates for Cervical Cancer As Identified by Differential Co-Expression Network Analysis

Cervical cancer is the second most common malignancy and the third reason for mortality among women in developing countries. Although infection by the oncogenic human papilloma viruses is a major cause, genomic contributors are still largely unknown. Network analyses, compared with candidate gene studies, offer greater promise to map the interactions among genomic loci contributing to cervical cancer risk. We report here a differential co-expression network analysis in five gene expression datasets (GSE7803, GSE9750, GSE39001, GSE52903, and GSE63514, from the Gene Expression Omnibus) in patients with cervical cancer and healthy controls. Kaplan-Meier Survival and principle component analyses were employed to evaluate prognostic and diagnostic performances of biomarker candidates, respectively. As a result, seven distinct co-expressed gene modules were identified. Among these, five modules (with sizes of 9-45 genes) presented high prognostic and diagnostic capabilities with hazard ratios of 2.28-11.3, and diagnostic odds ratios of 85.2-548.8. Moreover, these modules were associated with several key biological processes such as cell cycle regulation, keratinization, neutrophil degranulation, and the phospholipase D signaling pathway. In addition, transcription factors ETS1 and GATA2 were noted as common regulatory elements. These genomic biomarker candidates identified by differential co-expression network analysis offer new prospects for translational cancer research, not to mention personalized medicine to forecast cervical cancer susceptibility and prognosis. Looking into the future, we also suggest that the search for a molecular basis of common complex diseases should be complemented by differential co-expression analyses to obtain a systems-level understanding of disease phenotype variability.

Expression of HPV-induced DNA Damage Repair Factors Correlates With CIN Progression

Human papillomaviruses (HPVs) are DNA viruses with epithelial tropism. High-risk types of HPV are the causative agents of the majority of cervical cancers and are responsible for a number of other anogenital as well as oropharyngeal cancers. The life cycle of HPV is closely linked to the differentiation state of its host cell and is dependent on the activation of specific pathways of the DNA damage response. Several proteins from the ataxia telangiectasia mutated and the ataxia telangiectasia mutated and Rad3-related DNA repair pathways, which are essential for maintaining genomic stability in cells, are upregulated in HPV-positive cells and are required for viral replication. Our studies examine the expression of 5 such DNA repair factors-pCHK2, pCHK1, FANCD2, BRCA1, and H2AX-in cervical specimens from patients diagnosed with low-grade, intermediate-grade, or high-grade lesions. The percentage of cells expressing pCHK2, pCHK1, FANCD2, and BRCA1 is significantly higher in high-grade squamous intraepithelial lesions compared with that of either low-grade squamous intraepithelial lesions or normal tissue, particularly in differentiated cell layers. In addition, the distribution of this staining throughout the epithelium is altered with increasing lesion grade. This study characterizes the expression of pCHK2, pCHK1, FANCD2, H2AX and BRCA1 during cervical cancer progression and provides additional insight into the role of these DNA damage response proteins in viral transformation.

Genetic Susceptibility for Cervical Cancer in African Populations: What Are the Host Genetic Drivers?

Human papillomavirus (HPV) is an essential but not a sufficient cervical cancer etiological factor. Cancer promoters, such as host genetic mutations, significantly modulate therapeutic responses and susceptibility. In cervical cancer, of interest have been viral clearing genes and HPV oncoprotein targets, for which conflicting data have been reported among different populations. This expert analysis evaluates cervical cancer genetic susceptibility biomarkers studied in African populations. Notably, the past decade has seen Africa as a hotbed of biomarker and precision medicine innovations, thus potentially informing worldwide biomarker development strategies. We conducted a critical literature search in PubMed/MEDLINE, Google Scholar, and Scopus databases for case-control studies reporting on cervical cancer genetic polymorphisms among Africans. We found that seven African countries conducted cervical cancer molecular epidemiology studies in one of Casp8, p53, CCR2, FASL, HLA, IL10, TGF-beta, and TNF-alpha genes. This analysis reveals a remarkable gap in cervical cancer molecular epidemiology among Africans, whereas cervical cancer continues to disproportionately have an impact on African populations. Genome-wide association, whole exome- and whole-genome sequencing studies confirmed the contribution of candidate genes in cervical cancer. With such advances and omics technologies, the role of genetic susceptibility biomarkers can be exploited to develop novel interventions to improve current screening, diagnostic and prognostic methods worldwide. Exploring these genetic variations is crucial because African populations are genetically diverse and some variants or their combined effects are yet to be discovered and translated into tangible clinical applications. Thus, translational medicine and flourishing system sciences in Africa warrant further emphasis in the coming decade.

Association of single nucleotide polymorphisms in the CYBA gene with coal workers' pneumoconiosis in the Han Chinese population

Coal workers' pneumoconiosis (CWP) is caused by long-term exposure to inhaled coal dust; it is likely influenced by the interaction between environmental factors and multiple susceptibility genes, such as the CYBA (cytochrome b-245α polypeptide) gene that has recently been identified to be involved in the genetic susceptibility for several pulmonary diseases. The aim of this case-control study was to explore the association between CYBA gene polymorphisms and the development of CWP in coal miners belonging to the Han ethnic group in China. Single nucleotide polymorphisms (SNPs) rs7195830, rs13306296, rs4673, rs9932581, and rs16966671 of the CYBA gene were analyzed in CWP patients (n = 652) and dust-exposed control subjects (n = 648) using the matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) on the Sequenom MassARRAY® platform (Sequenom, San Diego, CA, USA). Results from the present study showed a strong allele association between CWP patients and the CYBA SNP rs7195830 polymorphism (p < .001, OR = 1.550). Using the additive and the dominant model, the CYBA SNP rs7195830 polymorphism also showed significant associations with CWP patients (p < .001, OR = 1.621; p = .003, OR = 1.711, respectively). No statistically significant difference was demonstrated in either the allele or genotype frequencies of the other four examined SNPs (rs13306296, rs4673, rs9932581, and rs16966671) between the CWP group and dust-exposed control group (all p > .05). The present study is the first to have demonstrated an association between CYBA (rs7195830) polymorphism and the risk of developing CWP in subjects belong to the Han ethnic group in China and provides further clues for research into the pathogenesis of CWP.

Association of IL-6 -174G>C (rs1800795) polymorphism with cervical cancer susceptibility

Interleukin-6 (IL-6) is a multifunctional cytokine that has been implicated in the etiology of cancer. Several case–control studies have been conducted to assess the association of IL-6 -174G>C (rs1800795) polymorphism with the risk of cervical cancer, yet with conflicting conclusions. To derive a more precise estimation of the relationship, we performed this meta-analysis updated to June 2018. A total of seven original publications were identified covering IL-6 -174G>C (rs1800795) polymorphism. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the relationship strengths. Statistically significant relationship was observed between IL-6 -174G>C polymorphism and cervical cancer risk (OR = 0.61, 95% CI: 0.40–0.94 for GG vs. CC, and OR = 0.77, 95% CI: 0.64–0.93 for G vs. C). Moreover, the significant association was found among Asians (OR = 0.46, 95% CI: 0.29–0.75 for GG vs. CC, and OR = 0.70, 95% CI: 0.57–0.89 for G vs. C); hospital-based subgroup (OR = 0.53, 95% CI: 0.38–0.72 for GG vs. CC, and OR = 0.73, 95% CI: 0.61–0.87 for G vs. C); and Hardy–Weinberg equilibrium ≤0.05 (OR = 0.56, 95% CI: 0.37–0.86 for GG vs. GC, and OR = 0.66, 95% CI: 0.47–0.93 for G vs. C). This meta-analysis showed the evidence that the IL-6 -174G>C polymorphism was a low-penetrance susceptibility variant for cervical cancer. Further large-scale case–control studies are needed to confirm these results.

Polymorphism Located in the Upstream Region of the RPS19 Gene (rs2305809) Is Associated With Cervical Cancer: A Case-control Study

Cervical cancer (CC) is caused by persistent human papillomavirus (HPV) infection and affects women worldwide. The progression of an HPV persistent infection to CC is influenced by genetic factors. Three single nucleotide polymorphisms (SNPs) in TP53, NQO1 and RPS19 genes (rs1042522, rs1800566, rs2305809, respectively) were previously associated with CC in European and North American populations. The present case-control study aimed to investigate the association of the SNPs rs1042522, rs1800566, and rs2305809 with CC in an admixed population in southern Brazil. A total of 435 women (106 CC patients and 329 controls) were recruited for this study. All women were interviewed and underwent clinical sampling. SNPs rs1042522 and rs1800566 were evaluated by PCR-RFLP. SNP rs2305809 was determined by real-time PCR. The crude and adjusted ORs with 95% CI were estimated. The recessive genetic model (C/C + C/T) for rs2305809 was more frequent in the control group (79.9%) compared to the cases (69.8%), being associated with CC protection (_adjustedOR = 0.49; 95% CI: 0.27–0.90). However, the other polymorphisms evaluated did not present significant differences between cases and controls. This study detected a protective association for the recessive genetic model in rs2305809. These results suggest a potential role of the RPS19 gene in CC.

Meta-analysis of XRCC1 polymorphism and risk of female reproductive system cancer

Numerous epidemiological studies have evaluated the association between polymorphism in the gene encoding x-ray repair cross complementing 1 (XRCC1) protein and the risk of female reproductive system cancer, but results are inconclusive. To gain a comprehensive picture of available evidence, we searched for relevant studies in the PubMed, EMBASE, Scopus, and Chinese National Knowledge Infrastructure databases up to December 17, 2016. A total of 26 case-control studies were picked out. The pooled odds ratio (OR) with its 95% confidence interval (CI) was calculated to estimate the association. Based on data of all study participants, we did not find a positive association of rs25487 or rs1799782 polymorphism with risk of female reproductive cancer risk. Subgroup analysis, however, identified two alleles as being associated with an increased risk of female reproductive system cancer in Asians: the A allele of rs25487 (heterozygous genetic model, OR 1.16, 95%CI 1.00-1.36), and the T allele of rs1799782 (homozygous model, OR 2.30, 95%CI 1.39-3.82; dominant model, OR 1.28, 95%CI 1.10-1.50; recessive model, OR 2.11, 95%CI 1.33-3.34). Moreover, the AA genotype at rs25489 was determined to be a risk factor for cervical cancer etiology (homozygous model, OR 2.91, 95%CI, 1.17-7.26; recessive model, OR 3.16, 95%CI 1.91-5.24). This meta-analysis suggests that no association between rs25487 or rs1799782 gene polymorphism and risk of female reproductive cancer risk was found. These results should be validated in larger studies.

Association between XRCC1 polymorphisms and the risk of cervical cancer: a meta-analysis based on 4895 subjects

The present meta-analysis was intended to explore the relationship between the X-ray repair cross complementing 1 (XRCC1) polymorphisms (Arg194Trp, Arg280His and Arg399Gln) and cervical cancer risk. Several electronic databases were searched systematically and bibliographies of relevant papers were identified carefully. Then, a meta-analysis was performed based on eligible studies in various genetic models. Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were employed to evaluate the strength of associations between the XRCC1 polymorphisms and cervical cancer risk. Additionally, heterogeneity analysis and sensitivity analysis were done if necessary. Totally, 11 articles involving 2092 cases and 2803 controls were included. Taken together, there was no obvious association between the Arg194Trp or Arg280His polymorphism and cervical cancer risk. Considering the great heterogeneity, subgroup analysis was done, but the pooled result remained stable. Nevertheless, the association between the Arg399Gln polymorphism and cervical cancer risk showed distinct statistic significance in the allele model, dominant model, homozygous model and heterozygous model. In view of the exiting heterogeneity, we did subgroup analysis stratified by ethnicity, resulting in the fact that the Arg399Gln polymorphism was related to the decreased risk of cervical cancer. The Begg's test and Egger's test were used to find no publication bias. To conclude, the current meta-analysis indicated that the XRCC1 Arg399Gln polymorphism decreased the risk of cervical cancer, while the Arg194Trp and Arg280His polymorphisms were not associated with cervical caner risk. Certainly, a well-designed large-scale multicenter study is warranted to confirm the finding.

Impact of DNA repair gene polymorphisms on the risk of biochemical recurrence after radiotherapy and overall survival in prostate cancer

The identification of biomarkers of biochemical recurrence (BCR) in prostate cancer (PCa) patients undergoing radiotherapy (RT) represents an unanswered clinical issue. The primary aim of this study was the definition of new genetic prognostic biomarkers in DNA repair genes (DRGs), considering both BCR and overall survival (OS) as clinical end-points. The secondary aim was to explore the potential clinical impact of these genetic variants with the decision curve analysis (DCA) and the sensitivity analysis.We analyzed 22 germline polymorphisms in 14 DRGs on 542 Caucasian PCa patients treated with RT as primary therapy. Significant associations were further tested with a bootstrapping technique. According to our analyses, ERCC2-rs1799793 and EXO1-rs4149963 were significantly associated with BCR (p = 0.01 and p = 0.01, respectively). Moreover, MSH6-rs3136228 was associated with a worse OS (p = 0.04). Nonetheless, the DCA and the sensitivity analyses gave no ultimate response about the clinical impact of such variants.This study highlights the potential prognostic role of polymorphisms in DRGs for PCa, paving the way to the introduction of not invasive tools for the personalization of patients management. Nonetheless, other prospective studies are necessary to ultimately clarify the clinical impact of pharmacogenetics in PCa.

Genetic susceptibility in cervical cancer: From bench to bedside

Cervical cancer (CC) is the third most common malignancy in women globally, and persistent infection with the oncogenic human papillomaviruses (HPV) is recognized as the major risk factor. The pathogenesis of CC relies on the interplay between the tumorigenic properties of the HPV and host factors. Host-related genetic factors, including the presence of susceptibility loci for cervix tumor is substantial importance. Preclinical and genome-wide association studies (GWAS) have reported the associations of genetic variations in several susceptibility loci for the development of cervical cancer. However, many of these reports are inconsistent. In this review, we discuss the findings to date of candidate gene association studies, and GWAS in cervical cancer. The associations between these genetic variations with response to chemotherapy are also discussed.

Defining the genetic susceptibility to cervical neoplasia-A genome-wide association study

A small percentage of women with cervical HPV infection progress to cervical neoplasia, and the risk factors determining progression are incompletely understood. We sought to define the genetic loci involved in cervical neoplasia and to assess its heritability using unbiased unrelated case/control statistical approaches. We demonstrated strong association of cervical neoplasia with risk and protective HLA haplotypes that are determined by the amino-acids carried at positions 13 and 71 in pocket 4 of HLA-DRB1 and position 156 in HLA-B. Furthermore, 36% (standard error 2.4%) of liability of HPV-associated cervical pre-cancer and cancer is determined by common genetic variants. Women in the highest 10% of genetic risk scores have approximately >7.1% risk, and those in the highest 5% have approximately >21.6% risk, of developing cervical neoplasia. Future studies should examine genetic risk prediction in assessing the risk of cervical neoplasia further, in combination with other screening methods.

Around 1% of women with cervical human papillomavirus (HPV) infection progress to cervical cancer. Previous studies had indicated that a person’s genetic makeup could predispose to HPV-associated cervical cancer, and that some of the genes likely to be involved include the immune-related human leukocyte antigen (HLA) genes among the major histocompatibility complex (MHC). However, it has been difficult to determine which alleles might be associated with cervical pre-cancer or cancer due to the complex and high level of co-inheritance of MHC alleles. Here, we performed a genome-wide association study that assessed the correlation of genetic variants among those with cervical cancer and healthy controls. We show that host genetics is a major determinant of HPV-associated cervical cancer, with 36% of liability due to common genetic variants in the population, and identify both risk and protective HLA alleles. Our study was also sufficiently powerful to identify particular residue variants on a number of the immune-related proteins that provide risk or protection, providing further insight into the biological basis for cervical cancer development. Our findings could lay the foundation for screening for people at increased risk of developing cancer following HPV infection, and aid in the treatment and prognosis of cervical cancer.

Putative biomarkers for cervical cancer: SNVs, methylation and expression profiles

Cervical cancer is primarily caused by Human papillomavirus (HPV) infection, but other factors such as smoking habits, co-infections and genetic background, can also contribute to its development. Although this cancer is avoidable, it is the fourth most frequent type of cancer in females worldwide and can only be treated with chemotherapy and radical surgery. There is a need for biomarkers that will enable early diagnosis and targeted therapy for this type of cancer. Therefore, a systems biology pipeline was applied in order to identify potential biomarkers for cervical cancer, which show significant reports in three molecular aspects: DNA sequence variants, DNA methylation pattern and alterations in mRNA/protein expression levels. CDH1, CDKN2A, RB1 and TP53 genes were selected as putative biomarkers, being involved in metastasis, cell cycle regulation and tumour suppression. Other ten genes (CDH13, FHIT, PTEN, MLH1, TP73, CDKN1A, CACNA2D2, TERT, WIF1, APC) seemed to play a role in cervical cancer, but the lack of studies prevented their inclusion as possible biomarkers. Our results highlight the importance of these genes. However, further studies should be performed to elucidate the impact of DNA sequence variants and/or epigenetic deregulation and altered expression of these genes in cervical carcinogenesis and their potential as biomarkers for cervical cancer diagnosis and prognosis.

Cervical Carcinogenesis and Immune Response Gene Polymorphisms: A Review

The local immune response is considered a key determinant in cervical carcinogenesis after persistent infection with oncogenic, high-risk human papillomavirus (HPV) infections. Genetic variation in various immune response genes has been shown to influence risk of developing cervical cancer, as well as progression and survival among cervical cancer patients. We reviewed the literature on associations of immunogenetic single nucleotide polymorphism, allele, genotype, and haplotype distributions with risk and progression of cervical cancer. Studies on HLA and KIR gene polymorphisms were excluded due to the abundance on literature on that subject. We show that multiple genes and loci are associated with variation in risk of cervical cancer. Rather than one single gene being responsible for cervical carcinogenesis, we postulate that variations in the different immune response genes lead to subtle differences in the effectiveness of the antiviral and antitumour immune responses, ultimately leading to differences in risk of developing cervical cancer and progressive disease after HPV infection.

Genetic polymorphisms of FAS and EVER genes in a Greek population and their susceptibility to cervical cancer: a case control study

BACKGROUND

The aim of the study was to evaluate the association of two SNPs of EVER1/2 genes' region (rs2290907, rs16970849) and the FAS-670 polymorphism with the susceptibility to precancerous lesions and cervical cancer in a Greek population.

METHODS

Among the 515 women who were included in the statistical analysis, 113 belong to the case group and present with precancerous lesions or cervical cancer (27 with persistent CIN1, 66 with CIN2/3 and 20 with cervical cancer) and 402 belong to the control group. The chi-squared test was used to compare the case and the control groups with an allelic and a genotype-based analysis.

RESULTS

The results of the statistical analysis comparing the case and the control groups for all the SNPs tested were not statistically significant. Borderline significant difference (p value = 0.079) was only found by the allelic model between the control group and the CIN1/CIN2 patients' subgroup for the polymorphism rs16970849. The comparison of the other case subgroups with the control group did not show any statistically significant difference.

CONCLUSIONS

None of the SNPs included in the study can be associated with statistical significance with the development of precancerous lesions or cervical cancer.

Pharmacogenetic research activity in Central America and the Caribbean: a systematic review

AIM

The present review was aimed at analyzing the pharmacogenetic scientific activity in Central America and the Caribbean.

MATERIALS & METHODS

A literature search for pharmacogenetic studies in each country of the region was conducted on three databases using a list of the most relevant pharmacogenetic biomarkers including 'phenotyping probe drugs' for major drug metabolizing enzymes. The review included 132 papers involving 47 biomarkers and 35,079 subjects (11,129 healthy volunteers and 23,950 patients).

RESULTS

The country with the most intensive pharmacogenetic research was Costa Rica. The most studied medical therapeutic area was oncology, and the most investigated biomarkers were CYP2D6 and HLA-A/B. Conclusion: Research activity on pharmacogenetics in Central American and the Caribbean populations is limited or absent. Therefore, strategies to promote effective collaborations, and foster interregional initiatives and research efforts among countries from the region could help for the rational clinical implementation of pharmacogenetics and personalized medicine.

The CYBA Gene (⁎)49A>G Polymorphism (rs7195830) Is Associated with Hypertension in Patients with Coronary Artery Disease

Purpose. Single nucleotide polymorphisms of the CYBA gene may modify the risk of coronary artery disease (CAD). The aim of the present study was to investigate whether the ^⁎49A>G (rs7195830) polymorphism is associated with CAD. Materials and Methods. CYBA gene ^⁎49A>G polymorphism was determined in 481 subjects: 242 patients with premature CAD and 239 age and sex matched controls using the fluorescently labeled allele-specific oligonucleotides method. Results. The frequency of the ^⁎49G allele carrier state was significantly higher in patients than in controls (84.8% versus 76.6%, resp., P = 0.020), as well as the frequency of the ^⁎49G allele (62.2% versus 54.0%, P = 0.009). Both factors were associated with CAD in the analyzed population (OR = 1.70, 95% CI: 1.04–2.76 for GG+AG versus AA and OR = 1.40, 95% CI: 1.08–1.83 for ^⁎49G versus  ^⁎49A). Carrier state of the ^⁎49G allele was a stronger and independent risk factor for CAD among women (OR = 4.35, 95% CI: 1.50–13.20, P = 0.002), as well as the ^⁎49G allele (OR = 2.25, 95% CI: 1.34–3.77, P = 0.001). The ^⁎49G allele carrier state was also associated with left ventricular hypertrophy in patients with coronary artery disease (P = 0.015). Conclusion. The CYBA gene ^⁎49A>G polymorphism modifies the risk of coronary artery disease.

Association between three exonuclease 1 polymorphisms and cancer risks: a meta-analysis

To date, the results of studies exploring the relation between exonuclease 1 (Exo1) polymorphisms and cancer risks have differed. In this study, we performed a meta-analysis to investigate the effect of the three most extensively studied Exo1 polymorphisms (Pro757Leu, Glu589Lys, and Glu670Gly) on cancer susceptibility. The related studies published before August 5, 2015, were collected by searching the PubMed and EMBASE databases. We found 16 publications containing studies that were eligible for our study, including 10 studies for Pro757Leu polymorphism (4,093 cases and 3,834 controls), 12 studies for Glu589Lys polymorphism (6,479 cases and 6,550 controls), and 7 studies for Glu670Gly polymorphism (3,700 cases and 3,496 controls). Pooled odds ratios and 95% confidence intervals were used to assess the strength of the associations, and all the statistical analyses were calculated using the software program STATA version 12.0. Our results revealed that the Pro757Leu polymorphism was significantly associated with a reduced cancer risk, whereas an inverse association was found for the Glu589Lys polymorphism. Furthermore, subgroup analysis of smoking status indicated that the Glu589Lys polymorphism was significantly associated with an increased cancer risk in smokers, but not in nonsmokers. However, no evidence was found for an association between the Glu670Gly polymorphism and cancer risk. In conclusion, this meta-analysis suggests that the Pro757Leu polymorphism may provide protective effects against cancer, while the Glu589Lys polymorphism may be a risk factor for cancer. Moreover, the Glu670Gly polymorphism may have no influence on cancer susceptibility. In the future, large-scaled and well-designed studies are needed to achieve a more precise and comprehensive result.

Association of single nucleotide polymorphisms in tumor necrosis factor-alpha with cervical cancer susceptibility

Tumor necrosis factor-alpha (TNF-α) polymorphisms have been reported to play an important role in the development of cervical cancer. But the results remain inconclusive. We performed this study to provide a comprehensive assessment of the association by means of a meta-analysis in which all published studies were included. The studies investigating the associations between cervical cancer risk and TNF-α polymorphisms were identified through PubMed, Embase, CNKI, and Chinese BioMedical Literature Database. OR and 95% CI (odds ratio and 95% confidence interval) were calculated using either the fixed or random effects model to assess the associations. We eventually included eighteen case-control studies of SNP -308 G>A and nine studies of SNP -238 G>A. Meta-analysis of the former polymorphism suggested significantly increased risk of cervical cancer associated with the A allele (OR 1.19, 95% CI 1.02-1.38). Subgroup analysis according to ethnicity showed similar results in Caucasians (A vs. G: OR 1.25, 95% CI 1.02-1.54; AA vs. GG: OR 1.47, 95% CI 1.04-2.08; AA vs. GA+GG: OR 1.47, 95% CI 1.04-2.08). For SNP -238 G>A, a protective association was observed in overall comparisons (A vs. G: OR 0.64, 95% CI 0.51-0.80; AA+GA vs. GG: OR 0.62, 95% CI 0.49-0.79) and subgroup analysis of Caucasians (A vs. G: OR 0.67, 95% CI 0.53-0.83; AA+GA vs. GG: OR 0.65, 95% CI 0.51-0.82). Our meta-analysis indicates that TNF-α polymorphisms may confer susceptibility to cervical cancer in an ethic-specific fashion.

Prevalence of human papilloma virus (HPV) and its genotypes in cervical specimens of Egyptian women by linear array HPV genotyping test

BACKGROUND

The association of human papillomavirus (HPV) with cervical cancer is well established.

AIM

To investigate HPV genotype distribution and co-infection occurrence in cervical specimens from a group of Egyptian women.

METHODS

A group of 152 women with and without cervical lesions were studied. All women had cervical cytology and HPV testing. They were classified according to cytology into those with normal cytology, with squamous intraepithelial lesions (SIL) and invasive squamous cell carcinoma (SCC). Cervical samples were analyzed to identify the presence of HPV by PCR, and all positive HPV-DNA samples underwent viral genotype analysis by means of LINEAR ARRAY HPV Genotyping assay.

RESULTS

A total of 26 HPV types with a prevalence of 40.8 % were detected. This prevalence was distributed as follows: 17.7 % among cytologically normal females, 56.5, 3.2, and 22.6 % among those with LSIL, HSIL and invasive SCC respectively. Low-risk HPV types were detected in 81.8 % of the cytologically-normal women, in 5.7 % of those in LSIL women, and in 14.3 % of infections with invasive SCC, while no low-risk types were detected in HSIL. High-risk HPV types were detected in 18.2 % of infections in the cytologically normal women, 14.3 % of infections in LSIL, and in 21.4 % of invasive lesions. The probable and possible carcinogenic HPV were not detected as single infections. Mixed infection was present in 80 % of women with LSIL, in 100 % of those with HSIL, and in 64.3 % of those with invasive SCC. This difference was statistically significant. HPV 16, 18 and 31 were the most prevalent HR HPV types, constituting 41.9, 29.03 and 12.9 % respectively, and HPV 6, 62 and CP6108 were the most prevalent LR HPV types constituting 11.3, 9.7 and 9.7 % respectively.

CONCLUSION

These data expand the knowledge concerning HPV prevalence and type distribution in Egypt which may help to create a national HPV prevention program. HPV testing using the LINEAR ARRAY HPV Genotyping assay is a useful tool when combined with cytology in the diagnosis of mixed and non-conventional HPV viral types.

Genetic diversity of HPV16 and HPV18 in Brazilian patients with invasive cervical cancer

Cervical cancer is the fourth most common cancer among women, and ∼70-80% of these cancers are associated with two human papillomavirus types: HPV16 and HPV18. Several studies have reported that intra-type diversity is associated with the progression of infection to invasive cancer. Herein, we report the genetic diversity of HPV16 and HPV18 in a cohort of 594 Brazilian women with invasive cervical cancer and describe the prevalence of lineages and intra-type diversity prior to the implementation of the public immunization program in Brazil. HPV detection and genotyping were performed using PCR, PGMY/GP primers, and DNA extracted from fresh tumors. The HPV16 (378 women) and HPV18 (80 women) lineages were identified by PCR and sequencing of the LCR and E6 fragments, followed by SNV comparison and phylogenetic analysis. In our cohort, was found a higher frequency of the lineage A (in 217 women), followed by lineage D (in 97 women) and lineages B and C (in 10 women each) for HPV16; and a higher frequency of lineage A (in 56 women) followed by lineage B (in 15 women) in HPV18. The genetic diversity of HPV16 indicated a recent expansion of specific variants or a selective advantage that is associated with invasive cancer; this pattern was not observed for HPV18.

In silico mechanistic analysis of IRF3 inactivation and high-risk HPV E6 species-dependent drug response

The high-risk human papillomavirus E6 (hrHPV E6) protein has been widely studied due to its implication in cervical cancer. In response to viral threat, activated kinases phosphorylate the IRF3 autoinhibitory domain, inducing type1 interferon production. HPV circumvents the antiviral response through the possible E6 interaction with IRF3 and abrogates p53's apoptotic activity by recruiting E6-associated protein. However, the molecular mechanism of IRF3 inactivation by hrHPV E6 has not yet been delineated. Therefore, we explored this mechanism through in silico examination of protein-protein and protein-ligand docking, binding energy differences, and computational alanine mutagenesis. Our results suggested that the LxxLL motifs of IRF3 binds within the hydrophobic pocket of E6, precluding Ser-patch phosphorylation, necessary for IRF3 activation and interferon induction. This model was further supported by molecular dynamics simulation. Furthermore, protein-ligand docking and drug resistance modeling revealed that the polar patches in the pocket of E6, which are crucial for complex stability and ligand binding, are inconsistent among hrHPV species. Such variabilities pose a risk of treatment failure owing to point mutations that might render drugs ineffective, and allude to multi-drug therapy. Overall, this study reveals a novel perspective of innate immune suppression in HPV infections and suggests a plausible therapeutic intervention.

Molecular transitions from papillomavirus infection to cervical precancer and cancer: Role of stromal estrogen receptor signaling

To study the multistep process of cervical cancer development, we analyzed 128 frozen cervical samples spanning normalcy, increasingly severe cervical intraepithelial neoplasia (CIN1- CIN3), and cervical cancer (CxCa) from multiple perspectives, revealing a cascade of progressive changes. Compared with normal tissue, expression of many DNA replication/repair and cell proliferation genes was increased in CIN1/CIN2 lesions and further sustained in CIN3, consistent with high-risk human papillomavirus (HPV)-induced tumor suppressor inactivation. The CIN3-to-CxCa transition showed metabolic shifts, including decreased expression of mitochondrial electron transport complex components and ribosomal protein genes. Significantly, despite clinical, epidemiological, and animal model results linking estrogen and estrogen receptor alpha (ERα) to CxCa, ERα expression declined >15-fold from normalcy to cancer, showing the strongest inverse correlation of any gene with the increasing expression of p16, a marker for HPV-linked cancers. This drop in ERα in CIN and tumor cells was confirmed at the protein level. However, ERα expression in stromal cells continued throughout CxCa development. Our further studies localized stromal ERα to FSP1+, CD34+, SMA- precursor fibrocytes adjacent to normal and precancerous CIN epithelium, and FSP1-, CD34-, SMA+ activated fibroblasts in CxCas. Moreover, rank correlations with ERα mRNA identified IL-8, CXCL12, CXCL14, their receptors, and other angiogenesis and immune cell infiltration and inflammatory factors as candidates for ERα-induced stroma-tumor signaling pathways. The results indicate that estrogen signaling in cervical cancer has dramatic differences from ERα+ breast cancers, and imply that estrogen signaling increasingly proceeds indirectly through ERα in tumor-associated stromal fibroblasts.

High-risk human papillomavirus targets crossroads in immune signaling

Persistent infections with a high-risk type human papillomavirus (hrHPV) can progress to cancer. High-risk HPVs infect keratinocytes (KCs) and successfully suppress host immunity for up to two years despite the fact that KCs are well equipped to detect and initiate immune responses to invading pathogens. Viral persistence is achieved by active interference with KCs innate and adaptive immune mechanisms. To this end hrHPV utilizes proteins encoded by its viral genome, as well as exploits cellular proteins to interfere with signaling of innate and adaptive immune pathways. This results in impairment of interferon and pro-inflammatory cytokine production and subsequent immune cell attraction, as well as resistance to incoming signals from the immune system. Furthermore, hrHPV avoids the killing of infected cells by interfering with antigen presentation to antigen-specific cytotoxic T lymphocytes. Thus, hrHPV has evolved multiple mechanisms to avoid detection and clearance by both the innate and adaptive immune system, the molecular mechanisms of which will be dealt with in detail in this review.

Association of human papillomavirus with Fanconi anemia promotes carcinogenesis in Fanconi anemia patients

Fanconi anemia (FA) is a rare recessive disorder associated with chromosomal fragility. FA patients are at very high risk of cancers, especially head and neck squamous cell carcinomas and squamous cell carcinomas caused by infection of human papillomaviruses (HPVs). By integrating into the host genome, HPV oncogenes E6 and E7 drive the genomic instability to promote DNA damage and gene mutations necessary for carcinogenesis in FA patients. Furthermore, E6 and E7 oncoproteins not only inhibit p53 and retinoblastoma but also impair the FANC/BRCA signaling pathway to prevent DNA damage repair and alter multiple signals including cell-cycle checkpoints, telomere function, cell proliferation, and interference of the host immune system leading to cancer development in FA patients. In this review, we summarize recent advances in unraveling the molecular mechanisms of FA susceptibility to HPV-induced cancers, which facilitate rational preventive and therapeutic strategies.

Association between tumor necrosis factor alpha rs1800629 polymorphism and risk of cervical cancer

PURPOSE

The objective of this study was to evaluate the influence of the TNF-α rs1800629 polymorphism on the risk of cervical cancer.

METHODS

A comprehensive search of EMBASE, PubMed, Wanfang database and China National Knowledge Infrastructure (CNKI) was conducted and the papers published were retrieved. The fixed effects or random effects model was appropriately used to calculate the odds ratio (OR) along with 95% confidence interval (CI).

RESULTS

Data from sixteen articles containing nineteen studies were summarized in this meta-analysis. In general, we observed a marginal association between the TNF-α rs1800629 polymorphism and cervical cancer risk under the AA + AG vs. GG comparison model (OR=1.17, 95% CI=1.00-1.38, P=0.019 for heterogeneity). Interestingly, significantly increased risk was observed in the allele model (A vs. G: OR=1.19, 95% CI=1.02-1.38, P=0.006 for heterogeneity). In the stratified analysis by ethnicity, we found significant results in Caucasians.

CONCLUSIONS

Our results reveal that the Caucasian population may be at increased risk of developing invasive cervical cancer associated with the TNF-α rs1800629 polymorphism.

Polymorphisms within the FANCA gene associate with premature ovarian failure in Korean women

OBJECTIVE

This study investigated whether polymorphisms within the Fanconi anemia complementation group A (FANCA) gene contribute to the increased risk of premature ovarian failure (POF) in Korean women.

METHODS

Ninety-eight women with POF and 218 controls participated in this study. Genomic DNA from peripheral blood was isolated, and GoldenGate genotyping assay was used to identify single nucleotide polymorphisms (SNPs) within the FANCA gene.

RESULTS

Two significant SNPs (rs1006547 and rs2239359; P < 0.05) were identified by logistic regression analysis, but results were insignificant after Bonferroni correction. Six SNPs formed a linkage disequilibrium block, and three main haplotypes were found. Two of three haplotypes (AAAGAA and GGGAGG) distributed highly in the POF group, whereas the remaining haplotype (GGAAGG) distributed highly in the control group by logistic regression analysis (highest odds ratio, 2.515; 95% CI, 1.515-4.175; P = 0.00036).

CONCLUSIONS

Our observations suggest that genetic variations in the FANCA gene may increase the risk for POF in Korean women.

Hypersensitivity to chemoradiation in FANCA carrier with cervical carcinoma-A case report and review of the literature

OBJECTIVE

Compared to Fanconi anemia (FA) patients with homozygous defective two-alleles inheritance, there is a scarce or no evidence on one defective allele FANCA carriers, with respect to their cancer incidence, clinical and in vitro radiosensitivity and chemosensitivity. On that account, we report a case of a 30-year old FANCA mutation carrier woman with uterine cervix adenocarcinoma who was treated with chemoradiotherapy, in which unexpected acute toxicity and fatal late morbidity occured.

METHODS

We also report the results of an in vitro test for radiosensitivity, immunohistochemical examination with FANCA staining and human papillomavirus genotypization, and a review of the literature for FA carrier patients with respect to cancer incidence, clinical and in vitro response to chemo/radiotherapy, options of early heterozygosity detection, and methods of in vitro prediction of hypersensitivity to oncologic treatment.

CONCLUSION

Although there are no standard guidelines for management of FA carriers with malignancies and reports about chemo- or radiosensitivity in this population are scarce; patients with FA-A heterozygosity may have a high rate of complications from chemo/radiotherapy. Up to now, an optimum method for the prediction of radiosensitivity and the best parameter has not been found. Clinical radioresponsiveness is unpredictable in FA carriers and there is a pressing need of new rapid and predictive in vitro assays of radiation responses. Until then, the treatment of FA carriers with malignancies should be individualized, with respect to potential hypersensitivity to ionizing radiation or cross-linking agents.

Functional variants in CYP1A1 and GSTM1 are associated with clearance of cervical HPV infection

OBJECTIVE

We evaluated time to clearance of high risk (HR) HPV infection in relation to functional variants in three genes (CYP1A1, GSTT1, and GSTM1).

METHODS

The study group consisted of 450 HR-HPV infected women from the Atypical squamous cells of undetermined significance-low-grade squamous intraepithelial Lesion Triage Study (ALTS) cohort followed up at the clinical center at Birmingham, Alabama. The Cox proportional hazard model with the Wei-Lin-Weisfeld (WLW) approach was used, controlling for relevant covariates.

RESULTS

Women who were polymorphic for CYP1A1 experienced an HR-HPV clearance rate that was 20% (HR=0.80, p=0.04) lower than women without the polymorphism for CYP1A1, adjusting for all other cofactors. The GSTM1 null genotype was associated with higher HR-HPV clearance rate (HR=1.39, p=0.006). The polymorphism in GSTT1 was not significantly associated with time to clearance of HR-HPV.

CONCLUSIONS

Xenobiotic metabolism genes may influence the natural history of HR-HPV infection and its progression to cervical cancer.

Lessons and implications from association studies and post-GWAS analyses of cervical cancer

Cervical cancer has a heritable genetic component. A large number of genetic associations with cervical cancer have been reported in hypothesis-driven candidate gene studies, but many of these results are either inconsistent or have failed to be independently replicated. Genome-wide association studies (GWAS) have identified additional susceptibility loci previously not implicated in cervical cancer development, highlighting the power of genome-wide unbiased association analyses. Post-GWAS analyses including pathway-based analysis and functional characterization of associated variants have provided new insights into the pathogenesis of cervical cancer. In this review we summarize findings from candidate gene association studies, GWAS, and post-GWAS analyses of cervical cancer. We also discuss gaps in our understanding, possible clinical implications of the findings, and lessons for studies of other complex diseases.